At present, a display device is applied widely. In a thin film transistor-liquid crystal display (TFT-LCD), gate driving signals are provided to gates of respective thin film transistors of a pixel region by a gate driving device. In technique of gate driver on array or gate on array (GOA), the gate driving device is formed on an array substrate of a liquid crystal display by array technology, so that the cost can be reduced and processes are simplified.
The gate driving device formed by the GOA technique comprises a plurality of shift register units, each of which is connected with a gate line of a thin film transistor of a pixel region. Specifically, the respective shift register units are connected with the gate lines of the thin film transistors of the pixel region formed by rows, and controlling turning on/turning off and so on is carried out on thin film transistors of corresponding rows by driving output signals output by the respective shift register units. For example, when a certain shift register unit outputs a driving output signal at a high level, thin film transistors of a row connected thereto are turned on. Then, the turned-on thin film transistors of the row controls brightness according to a signal output by a data driving device.
As described above, in the display device, when the shift register unit cannot operate normally, the display device cannot display normally. Therefore, requirement for the stability of the shift register unit becomes higher.